A Cannon 'Stun Gun'

Israeli Device Harnesses Shock Waves for Homeland Defense

Jan. 11, 2010 - 03:45AM
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TEL AVIV - An Israeli-developed shock wave cannon used by farmers to scare away crop-threatening birds could soon be available to police and homeland security forces around the world for nonlethal crowd control and perimeter defense.

Israel's Ministry of Defense recently approved a license for ArmyTec, a Netanya, Israel, technology development advisory firm, to market military and paramilitary versions of the Thunder Generator cannon.

Developed and produced for the agricultural industry by PDT Agro, a small firm based in Herzliya, Israel, the system detonates a mixture of common liquefied petroleum (LPG), cooking gas and air to generate a series of loud, stunning shock waves.

Using a patented process involving Pulse Detonation Technology (PDT), the system feeds the gas-air mixture into one or more so-called impulse chambers or cannon barrels, where the burning fuel detonates and intensifies in force as it travels through the chamber, exiting in a rapid-fire succession of high-velocity shock bursts.

A small battery-powered control system - about twice the size of a pack of cigarettes - measures fuel pressure, temperature and flow rates while monitoring the continuous intake of the air-gas mixture.

According to company data, the system generates 60 to 100 bursts per minute, each traveling at about 2,000 meters per second and lasting up to 300 milliseconds.

The resulting shocks create a double deterrent to rioters and potential intruders, developers here say, by the extreme air pressure and sonic boom effect generated once the mixture propagates and expands through the air. One standard 12-kilogram LPG gas canister (retail cost: about $25) can produce up to 5,000 shock bursts.

"That's more than enough for hours of continuous operation," said ArmyTec President Shlomo Tabak, a former Israeli military special operations officer, whose command positions included anti-terror training and oversight of Special Forces development programs.

"It's all done in a controlled and safe manner, using the cheapest, cleanest fuel available. The trick is to cause it not to burn, but to explode," said Igor Fridman, president of PDT Agro, who developed the system.

Fridman, a former Soviet scientist specializing in the physics of combustion and detonation, worked for years at the Institute for Ecologically Safe Technologies in Novosibirsk, Russia. After immigrating to Israel in 1991, he teamed with Bezelel Liberman, an explosives expert and former officer in the Israeli military's Engineering Corps and the Israel Police, to adapt the pulse detonation technology for commercial and industrial use.

With start-up funding from Israel's Chief Scientist's Office, the two established PDT Agro and began producing precursors of the Thunder Generator as an alternative to hazardous chemicals.

"Because we can control the power of the shock waves, we found we can use the process for many applications, including military, police and peripheral security missions," Liberman said. "It's much safer, cheaper and in many cases [more] politically acceptable than other explosive materials."

As for range, it all depends on the size of the cannon, Tabak said. The operational prototype demonstrated over the past six months to representatives of Israel's Ground Forces Command, Central Command and Israeli Police features a 5-inch barrel with a range of 30 to 50 meters.

"But if we make some changes in the diameter, our data shows we'll go up to 70 to 100 meters, without any other changes to the system," Tabak said.

If fired at less than 10 meters, the Thunder Generator could be lethal or inflict permanent damage, Fridman said. But when employed as intended at ranges of 30 meters or more, test data show that the shock waves will pass through people and objects without any lasting effects.

"Anyone within 30 to 50 meters from the cannon will feel like he's standing in front of a firing squad," he said. "He'll feel and hear the blast, but he won't be hurled to the ground. He'll be able to run away unharmed … and that's the point of this application."

Thunder Generator developers secured a U.S. patent on their system in mid-2009. In addition to its intended nonlethal effects on targets, they insist the system is safe and simple to use.

Menial laborers at Israeli farms and fisheries have been trained in less than 30 minutes, Liberman said, to operate the cannon to scare away birds migrating between Europe and Africa. He said nearly a dozen systems have been operating accident-free in Israel for nearly two years.

Multiple Missions, Configurations

Tabak said the Thunder Generator is adaptable for multiple missions, including defense of sensitive installations and hostage-rescue operations. Modular nozzles can control output, allowing shock waves to be calibrated and programmed to meet various tactical mission requirements, he said.

By affixing bended barrels to the pulse detonation system, Thunder Generator also can shoot at 90-degree angles, delivering shock waves around walls or other obstacles, Tabak said.

"We're talking about a working system. There are no technology gaps; it's all a matter of adapting the configuration to a specific operational concept," he said.

A senior MoD development official said voluminous data on potential physiological side effects of nonlethal and so-called less-than-lethal systems must be gathered before turning them over to operational users. He said the Ministry of Defense puts a premium on systems proven to be safe, inexpensive and effective at ranges of less than 100 meters.

Ephraim Sneh, a former Israeli defense minister, said more effort should be put into deploying such systems. "Use of nonlethal means saves lives and helps prevent violent deterioration of riots and mass protests," he said.

Sneh said the Thunder Generator is a good example of a safe, inexpensive and simple alternative to the use of lethal force. å